Callus ia a completely natural acquired, superficial, round, and thickened patch of epidermis caused by pressure or friction on the hands or feet. Heels and the balls of feet are especially prone to callus. While calluses serve a purpose to protect the underlying skin from damage, they are unsightly and can be painful. Severely callused skin can become so thick and dry that it cracks. For long-term positive results, nail professionals should employ a thorough treatment plan that encompasses removal and ongoing prevention.